Fault annunciation for a fan coil

ABSTRACT

An annunciation system for an HVAC fan coil unit is disclosed, comprising: (a) a housing having a front panel defining an opening for maintenance of a component inside the housing; (b) spaced apart LED&#39;s arranged in a row on a substrate that is mounted horizontally on the front panel adjacent to the opening; (d) a door mounted offset to the front panel and covering the opening and the LED&#39;s; and (e) an electronic controller coupled to memory. The electronic controller is configured to automatically energize predetermined ones of the LED&#39;s to emit light. Light emitted from the energized LED&#39;s is deflected by the door onto exposed portions of the front panel to cast an indirectly visible glow indicative of a status, condition, or fault of the HVAC fan coil unit.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 62/968,706, filed on Jan. 31, 2020, which is incorporated by reference herein in its entirety.

BACKGROUND

The instant disclosure relates generally to heating, ventilation, and air conditioning (HVAC) systems, and particularly to fault annunciation systems for use with one or more aspects of such systems.

Building management systems are often used to remotely control a plurality of HVAC units positioned throughout a building, such as a hotel, hospital office building, and the like. Such building management systems may send and receive signals and/or data to and from such HVAC units. Such signals or data may constitute a fault or maintenance condition of one or more of the HVAC units to alert maintenance staff to conduct maintenance or to repair/reset a fault condition affecting the operation of one or more of the HVAC units.

A common fault condition for an HVAC fan coil unit includes blockage of the condensate draining system and dirty filters. A sensor on the HVAC fan coil unit can alert maintenance technicians of the fault via the building management system. Technicians using the building management system may attempt to remotely troubleshoot the condition or shutdown the unit. Remotely shutting down the unit may hamper the technician staff at the building from restoring the unit to working condition.

In situations where no building management system exists, then maintenance crews must visit each of the HVAC units, open a door or panel, and visually inspect components inside the units to determine whether any fault conditions exist. The step of opening the door and looking inside is cumbersome, intrusive, and time consuming for maintenance staff. In situations where a visual status indicator is present, such as a gas pilot light, they lack visual aesthetic and are otherwise obtrusive to people who are in relatively close proximity to the HVAC fan coils unit and who are not tasked with identifying an operational status or condition of the HVAC fan coil units. In addition, such visual indicators lack the ability to be electronically controlled on and off to signal a selectable plurality of operational statuses or fault conditions.

What is needed, therefore, is a system that solves these problems in situations where no remote means exist for assessing a status, fault or maintenance condition of an HVAC fan coil unit.

SUMMARY

Disclosed herein are various embodiments of an annunciation system for an HVAC fan coil system. In one embodiment, an annunciation system for an HVAC fan coil unit includes: (a) a housing for the HVAC fan coil unit comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front frame comprising a front recessed panel, the front recessed panel defining an opening sized to permit maintenance of one or more components inside the housing; (b) a light emitter comprising a plurality of spaced apart light sources arranged in a row on a substrate, the substrate mounted horizontally on a front recessed face above and adjacent to the opening; (c) a movable door pivotally mounted to the front recessed panel and configured to overlap the opening and the light emitter, the door pivotally operable between a first, closed position and a second, open position, the door lying approximately parallel to and forwardly offset from the front recessed panel and the light emitter when in a fully closed position; and (d) an electronic controller coupled to memory, the electronic controller configured to electrically energize the light emitter to emit light, where light emitted from the light emitter is deflected by the door onto exposed portions of the front recessed panel to cast an indirectly visible glow indicative of a status, condition, or fault of the HVAC fan coil unit.

The electronic controller may include a microprocessor mounted on a printed circuit board. The printed circuit board may include an output port connected to the light emitter. The annunciator system may include an electrical cable connected to the output port on one end of the cable and to the light emitter on an opposite end of the cable.

The HVAC fan coil may be configured for installation in a guest room at a hotel, a condominium, or an apartment. Light from the energized light emitter may be emitted in one of a plurality of colors where each of the colors conveys a different status, condition, or fault of the HVAC fan coil unit. Light from the energized light emitter may alternatively be emitted in a predetermined on/off repeating pattern.

In another embodiment, an annunciation system for an HVAC fan coil unit includes: (a) a housing comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front panel defining an opening sized to permit maintenance of one or more components inside the housing; (b) a plurality of spaced apart LED's arranged in a row on a substrate that is mounted horizontally on the front panel adjacent to the opening; (c) a door pivotally mounted to the front panel and configured to overlap the opening and cover the LED's, the door lying approximately parallel to and forwardly offset from the front panel and the LED's; and (d) an electronic controller coupled to memory, the electronic controller configured to electrically and automatically energize predetermined ones of the LED's to emit light, where light emitted from the energized LED's is deflected by the door onto exposed portions of the front panel to cast an indirectly visible glow indicative of a status, condition, or fault of the HVAC fan coil unit.

The electronic controller may include a microprocessor mounted on a printed circuit board. The printed circuit board may include an output port connected to the LED's. The annunciation system may include an electrical cable that electrically connects the output port to at least one of the LED's.

In another embodiment, an annunciation system for an HVAC fan coil unit includes: (a) a housing comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front panel defining an opening sized to permit maintenance of one or more components inside the housing; (b) at least one light source on a substrate, the substrate mounted to the front panel and adjacent to the opening; (c) a cover mounted to and parallel to and offset from the front panel, the cover overlapping the opening and covering the at least one light source; and (d) an electronic controller coupled to memory, the electronic controller configured to electrically and automatically energize a predetermined one of the at least one light source to emit light, where light emitted from the energized at least one light source is deflected by the cover onto exposed portions of the front panel to cast an indirectly visible glow indicative of a status, condition, or fault of the HVAC fan coil unit.

The electronic controller may include a microprocessor mounted on a printed circuit board. The printed circuit board may include an output port connected to the at least one light source. The annunciation system may include an electrical cable that electrically connects the output port to the at least one light source, and the at least one light source comprises at least one LED.

In another embodiment, an annunciation system for an HVAC fan coil unit includes: (a) a housing comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front panel, wherein the front panel is removable to permit maintenance of one or more components inside the housing, the front panel comprising a plurality of louvres to permit return air to be drawn into the HVAC fan coil unit; (b) at least one LED on at least one substrate, the at least one substrate mounted to a frame member inside the housing; and (c) an electronic controller coupled to memory, the electronic controller configured to electrically and automatically energize a predetermined one of the at least one LED on the at least one substrate to emit light, where light emitted from the energized at least one LED is allowed to pass through at least one of the louvres to convey a status, condition, or fault of the HVAC fan coil unit.

The at least one substrate may include a pair of substrates. Each of the substrates may include a plurality of spaced apart LED's arranged in at least one row. Each of the substrates may be mounted inside the housing in proximity to at least some of the plurality of louvres. Light from the energized at least one LED may include one of a plurality of colors, where each of the colors conveys a different status, condition, or fault of the HVAC fan coil unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a partial front perspective view of a fan coil housing including a door panel shown in the closed position and with one embodiment of a fault annunciation system of the instant disclosure illustrating a non-fault condition.

FIG. 1B is a partial front perspective view of the fan coil housing of FIG. 1A shown with the door panel in the closed position and with the fault annunciation system illustrating a fault condition.

FIG. 2 is a partial front detail perspective section view of the fan coil housing of FIG. 1B with the fault annunciation system illustrating a fault condition.

FIG. 3 is partial front detail perspective view of the fan coil housing of FIG. 1B including the door panel shown in the open position and with the fault annunciation system illustrating a fault condition.

FIG. 4 is a front perspective view of a fan coil housing including a plurality of air vent openings and with another embodiment of a fault annunciation system of the instant disclosure illustrating a fault condition.

FIG. 5 is a front perspective section view of the fan coil housing of FIG. 4 with the fault annunciation system illustrating a fault condition.

DETAILED DESCRIPTION

Although the figures and the instant disclosure describe one or more embodiments of an annunciation system for an HVAC fan coil unit, one of ordinary skill in the art would appreciate that the teachings of the instant disclosure would not be limited to these embodiments. It should be appreciated that any of the features of an embodiment discussed with reference to the figures herein may be combined with or substituted for features discussed in connection with other embodiments in this disclosure.

Various embodiments for visual notification of the status, condition, and/or fault of an HVAC system, such as an HVAC fan coil unit, are disclosed herein. In some embodiments of the instant disclosure, the structure and air space behind a decorative perimeter panel or door of an HVAC unit, such as an HVAC fan coil housing, can be used to illuminate an area to signal to a passerby, such as a service technician, that a fault condition exists that requires service/maintenance attention. In one embodiment, one or more light sources may be positioned at least partially behind the decorative perimeter panel or door of the housing. The one or more light sources may include one or more LED's, one or more incandescent bulbs, one or more fluorescent bulbs, or one or more or other light sources known now or in the future. When the decorative panel or door of the housing is in a closed or stowed position, the one or more light sources may be hidden from direct view by a passerby. Thus, regardless of whether the one or more light sources is illuminated or not, the one or more light source devices themselves are not directly visible to a passerby without opening or unstowing the decorative panel or door.

In some embodiments, when the one or more hidden light sources illuminate to represent a condition or status, such as a fault condition, associated with the operation or maintenance of the HVAC fan coil unit, the light generated from the one or more hidden lights sources create an indirect/backlight signal that may be visible to a passerby who may be, for example, intending to ascertain the operational status of the HVAC fan coil unit without opening any doors, panels, etc. to peer inside the housing. The light may be unobtrusive yet at least partially noticeable by a service technician when the technician views or visually scans the exterior of the HVAC fan coil unit. The light from the one or more hidden light sources may be subtle in intensity after being reflected off of rear-facing features of the HVAC fan coil unit, such as the rear wall of the decorative perimeter panel or door. In some embodiments, the panel or door may act as a shield and/or a reflector that is designed to attenuate the light intensity of the reflected light. The light may illuminate a rear surface of the decorative perimeter panel or door and cast at least a dim glow on nearby surfaces of the HVAC fan coil housing. The backlit surfaces and neighboring surfaces of the housing that are illuminated by the one or more hidden light sources may provide an unobtrusive, low intensity, low lumen signal or glow indicative of a fault or maintenance status or condition to maintenance staff while also not disturbing anyone, such as hotel guests sleeping in close proximity to the installed HVAC fan coil unit.

In some embodiments, the one or more hidden light sources are configured to emit a single color of visible light. In other embodiments, the one or more hidden light sources are configured to emit a plurality of colors of visible light. In some embodiments, the one or more hidden light sources may emit light in a wavelength that is invisible to humans, such as infrared or ultraviolet light, yet detectable by a handheld detector, such as an infrared detector or an ultraviolet light detector, used by a maintenance technician. In some embodiments, a plurality of hidden light sources may be configured to emit a different color of visible or infrared light from each of the other hidden light sources. In some embodiments, the one or more hidden light sources may be configured to turn on and turn off in a predetermined sequence, a predetermined on/off time period, and/or a predetermined quantity of on/off cycles and any combination thereof to enable the one or more hidden light sources to indicate a plurality of operational statuses or conditions of the HVAC fan coil unit. In some embodiments, a predetermined one or more, but fewer than all, of the plurality of hidden light sources may be configured to illuminate to signal an operational status or condition of the HVAC fan coil unit while the other hidden light sources are not illuminated. In some embodiments, the one or more hidden lights sources may be triggered to emit light in a repeating or a non-repeating pattern.

The various embodiments disclosed herein offer the advantages of immediate, inexpensive, and efficient notification to maintenance staff of an HVAC fan coil unit status or fault condition without disturbing nearby people and without having to open the housing of the HVAC fan coil unit. Consequently, the various embodiments disclosed herein allow HVAC fan coil units that are not electronically connected with a building management system for fault detection and yet are installed in hotel rooms, for example, may provide visual or readily ascertainable information of a fault or maintenance condition to passerby hotel maintenance staff without being readily noticeable or disturbing to hotel guests in the hotel room. The various embodiments disclosed herein are agnostic to any type of thermostat or building management system that may be employed in connection with the HVAC fan coil unit to condition air in a desired space. In addition, the various embodiments disclosed herein provide indirect visual signaling of the operational status or condition of the HVAC fan coil unit to a building technician without disturbing customers or guests in the vicinity of the HVAC fan coil unit. The various embodiments disclosed herein provide the advantage of an aesthetic visual signaling system to avoid disturbing or obtrusively alerting customers or nearby guests.

Turning now to the drawings and to FIGS. 1A, 1B, and 2-6 in particular, there are shown various embodiments of an annunciation system 100 for an HVAC fan coil unit to communicate a status, condition, or fault condition or message to a technician without requiring the technician to open HVAC fan coil unit to peer inside. FIG. 1A shows annunciation system 100 in an “off” position indicative of either the normal operation of HVAC fan coil unit 105 or a total shutdown of HVAC fan coil unit 105. By contrast, FIG. 1B shows annunciation system 100 in an “on” position indicative of a visual notification of a status, condition, or fault of HVAC fan coil unit 105.

HVAC fan coil unit 105 includes housing 110 that houses or supports one or more components of HVAC fan coil unit 105. Housing 110 includes opposed side panels 112 connected to opposed top and bottom panels 114,115, a rear panel (not shown), and front frame 130 comprising opening 116 sized to permit maintenance or repair of one or more components inside housing 110. Housing 110 also includes movable panel or door 120 pivotally mounted, along one edge of movable panel or door 120 by one or more hinges 125, to front recessed face 131 of front frame 130 positioned opposite to the rear panel. Along the opposite edge of movable panel or door 120, housing 110 includes one or more panel or door catches, closures, or clasps 145, which may include any magnetic or non-magnetic closure mechanism or scheme known in the art. Front recessed face 131 of front frame 130 forms recessed area 132 to provide the advantage of having a plurality of surfaces upon which reflected light from status or fault annunciation system 100 may be captured, contained or deflected to avoid disturbing nearby guests by preventing the light from being directly visible when viewing the HVAC fan coil unit 105 from the side. In other embodiments, front frame 130 may not include a front recessed area 132.

As shown in FIG. 3, the one or more hinges 125 and the one or more panel or door latches, closures, or clasps 145 include extensions 126 and 146, respectively. The one or more hinges 125 and the one or more panel or door latches, closures, or clasps 145, via respective extensions 126 and 146, extend away from the front recessed face 131 of front frame 130 to cause the movable panel or door 120 to lie approximately parallel to and forwardly offset from the front recessed face 131 of front frame 130 when the movable panel or door 120 is in the closed position (see, e.g., FIGS. 1A, 1B, and 2) to allow return air from the space to enter through the perimeter gap 150 formed thereby.

HVAC fan coil unit 105 includes one or more electronic controllers in the form of one or more CPU's coupled to memory with software stored thereon. The one or more electronic controllers may be disposed on one or more printed circuit boards 140 for controlling the operation of HVAC fan coil unit 105 and for electrically energizing the one or more light emitters 160.

In various embodiments, the one or more light emitters 160 include one or more LED's, incandescent bulbs, fluorescent bulbs, text displays, or any device or combination thereof that emits light and/or text to communicate a message to a technician. For example, in some embodiments, the one or more light emitters 160 may include one or more LED's together or in combination with a display of text, where the LED's provide an initial, backlit, visual indication of a status, condition, or fault of HVAC fan coil unit 105 to trigger the technician to open movable panel or door 120 or remove/open an access panel to see accompanying text displayed on a computer display to further help the technician identify the nature of the status, condition, or fault of the HVAC fan coil unit 105. The text displayed on the computer display may be presented in English or any other language, or may instead be an alpha, alphanumeric, numeric, symbolic, or other code that can be decoded by the technician.

In the embodiments shown in the figures, the one or more light emitters 160 are configured to include a plurality of LED's 165 arranged on a substrate 170. Mounting the plurality of LED's 165 on substrate 170 provides the advantage of easily mounting the one or more light emitters 160 onto a surface of housing 110 and easily dismounting the one or more light emitters 160 should replacement be required. In other embodiments, each of LED's 165 may be mounted on individual substrates, or at least in smaller groups of LED's than shown in the figures. The plurality of LED's 165 may be arranged in any desired pattern on the substrate 170. In other embodiments, each of the LED's 165 may be mounted individually on a surface of housing 110.

In the embodiment of FIGS. 1A, 1B, and 2-3, the LED's 165 are spaced apart and arranged in a row on substrate 170, and substrate 170 is mounted approximately generally horizontally on front recessed face 131 of front frame 130 to enable the one or more light emitters 160 to lie hidden from direct view behind the movable panel or door 120, which is sized to overlap the opening 116 and cover the one or more light emitters 160, when the movable panel or door 120 is in the closed position. Mounting the one or more light emitters 160 in this way provides an aesthetically pleasing solution by taking advantage of the perimeter gap 150 formed between the rear face of movable panel or door 120 and the front recessed face 131 of front frame 130 that exists to allow return air from the space to be drawn into HVAC fan coil unit 105 for conditioning by HVAC fan coil unit 105. In other embodiments, substrate 170 may be affixed to a rear surface of the movable panel or door 120, with the LED's 165 facing rearwardly when the movable panel or door 120 is in the closed or stowed position. In some embodiments, the LED's 165 may be arranged on substrate 170 in multiple rows and/or in multiple different patterns or spacing with respect to one another. In some embodiments, LED's 165 comprises a single LED.

The one or more printed circuit boards 140 may include output port 175 for conveying a status or fault condition signal to the one or more light emitters 160. Output port 175 may be connected to the one or more light emitters 160 via cable 176.

During operation of the HVAC fan coil unit 105, annunciation system 100 may be activated if the one or more electronic controllers detects or determines, via one or more sensors, elapsed time, or other means, an operational status, condition, or fault message that the one or more electronic controllers is programmed to communicate to a technician. Upon registering the status, condition, or fault of one or more aspects of the HVAC fan coil unit 105, the one or more electronic controllers may energize the one or more light emitters 160 to illuminate at least one of the LED's 165 in any of the ways described above. Light 190 is deflected by rearwardly facing surfaces of panel or door 120 so as to cast an indirectly visible glow onto exposed portions of the front recessed panel 131 indicative of a status, condition, or fault of the HVAC fan coil unit 105 or component thereof.

Turning to FIGS. 4-5, there is shown another embodiment of an HVAC fan coil unit, in this case HVAC fan coil unit 205 having annunciation system 100. FIG. 4 shows annunciation system 100 in an “off” position indicative of either the normal operation of HVAC fan coil unit 205 or a total shutdown of HVAC fan coil unit 205. By contrast, FIG. 5 shows annunciation system 100 in an “on” position indicative of a visual notification of a status, condition, or fault of HVAC fan coil unit 205.

HVAC fan coil unit 205 includes housing 210 that houses at least portions of an HVAC refrigerant circuit and refrigerant circuit components therein. Housing 210 includes opposed side panels 212 connected to opposed top and bottom panels 214,215, rear panel, upper front panel 216, and lower front recessed panel 217. Upper front panel 216 includes louvres 220, and lower front recessed panel 217 includes louvres 221. Louvres 220,221 may be configured to allow return air from the space to be drawn into HVAC fan coil unit 205 for conditioning by HVAC fan coil unit 205.

HVAC fan coil unit 205 includes one or more electronic controllers in the form of one or more CPU's coupled to memory with software stored thereon. The one or more electronic controllers may be disposed on one or more printed circuit boards 240 for controlling the operation of HVAC fan coil unit 205 and for electrically energizing one or more light emitters 160.

As described above, in the embodiments shown in the figures, the one or more light emitters 160 are configured to include a plurality of LED's 165 arranged on a substrate 170. In the embodiment of FIGS. 4-5, the LED's 165 are arranged linearly with respect to one another on respective substrates 170, and the respective substrates 170 are mounted approximately generally horizontally on a frame member located inside housing 210 and in proximity to and behind louvres 220,221. In this way, the one or more light emitters 160, in this embodiment a pair of light emitters 160, lie hidden from direct view behind the respective upper and lower front panels 216,217 of housing 210, yet light (or invisible wavelength emission) from the plurality of LED's is unobtrusively visible or detected through the louvres 220,221. Mounting the one or more light emitters 160 in this way provides an aesthetically pleasing solution by taking advantage of the openings created by louvres 216,217 to allow return air from the space to be drawn into HVAC fan coil unit 205 for conditioning by HVAC fan coil unit 205 while minimizing or eliminating disturbance to nearby people. In some embodiments, only one light emitter 160 may be mounted inside housing 210. In other embodiments, more than two light emitters 160 may be mounted inside housing 210. In the embodiment of FIGS. 4-5, the one or more light emitters 160 may be configured and/or be operated in any of the ways described above. In other embodiments, as described above, the one or more light emitters 160 may be configured to include one or more LED's together or in combination with a display of text, where the LED's provide an initial, backlit, visual indication of a status, condition, or fault of HVAC fan coil unit 205 to trigger the technician to remove/open an access panel, such as upper front panel 216, to see accompanying text displayed on a computer display to further help the technician identify the nature of the status, condition, or fault of the HVAC fan coil unit 205. The text displayed on the computer display may be presented in English or any other language, or may instead be an alpha, alphanumeric, numeric, symbolic, or other code that can be decoded by the technician.

The one or more printed circuit boards 240 may include output port 275 for conveying a status or fault condition signal to the one or more light emitters 160. Output port 275 may be connected to the one or more light emitters 160 via cables 276.

During operation of the HVAC fan coil unit 205, annunciation system 100 may be activated if the one or more electronic controllers detects or determines, via one or more sensors, elapsed time, or other means, an operational status, condition, or fault message that the one or more electronic controllers is programmed to communicate to a technician. Upon registering the status, condition, or fault of one or more aspects of the HVAC fan coil unit 205, the one or more electronic controllers may energize the one or more light emitters 160 to illuminate at least one of the LED's 165 in any of the ways described herein. At least a portion of light 190 emitted from LED's 165 is allowed to pass through louvres 220,221 to convey to a technician a status, condition, or fault of the HVAC fan coil unit 105 or component thereof without having to open the housing 210. When LED's 165 are energized, the backlit upper front panel 216 and lower front panel 217 causes

While specific embodiments have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the disclosure herein is meant to be illustrative only and not limiting as to its scope and should be given the full breadth of the appended claims and any equivalents thereof. 

1. An annunciation system for an HVAC fan coil unit, comprising: a housing for the HVAC fan coil unit comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front frame comprising a front recessed panel, the front recessed panel defining an opening sized to permit maintenance of one or more components inside the housing; a light emitter comprising a plurality of spaced apart light sources arranged in a row on a substrate, the substrate mounted horizontally on a front recessed face above and adjacent to the opening; a movable door pivotally mounted to the front recessed panel and configured to overlap the opening and the light emitter, the door pivotally operable between a first, closed position and a second, open position, the door lying approximately parallel to and forwardly offset from the front recessed panel and the light emitter when in a fully closed position; and an electronic controller coupled to memory, the electronic controller configured to electrically energize the light emitter to emit light, wherein light emitted from the light emitter is deflected by the door onto exposed portions of the front recessed panel to cast an indirectly visible glow indicative of a status, condition, or fault of the HVAC fan coil unit.
 2. The annunciation system of claim 1, wherein the electronic controller comprises a microprocessor mounted on a printed circuit board.
 3. The annunciation system of claim 2, wherein the printed circuit board includes an output port connected to the light emitter.
 4. The annunciation system of claim 3, including an electrical cable connected to the output port on one end of the cable and to the light emitter on an opposite end of the cable.
 5. The annunciation system of claim 1, wherein the HVAC fan coil is configured for installation in a guest room at a hotel, a condominium, or an apartment.
 6. The annunciation system of claim 1, wherein light from the energized light emitter is emitted in one of a plurality of colors, wherein each of the colors conveys a different status, condition, or fault of the HVAC fan coil unit.
 7. The annunciation system of claim 1, wherein light from the energized light emitter is emitted in a predetermined on/off repeating pattern.
 8. An annunciation system for an HVAC fan coil unit, comprising: a housing comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front panel defining an opening sized to permit maintenance of one or more components inside the housing; a plurality of spaced apart LED's arranged in a row on a substrate that is mounted horizontally on the front panel adjacent to the opening; a door pivotally mounted to the front panel and configured to overlap the opening and cover the LED's, the door lying approximately parallel to and forwardly offset from the front panel and the LED's; and an electronic controller coupled to memory, the electronic controller configured to electrically and automatically energize predetermined ones of the LED's to emit light, wherein light emitted from the energized LED's is deflected by the door onto exposed portions of the front panel to cast an indirectly visible glow indicative of a status, condition, or fault of the HVAC fan coil unit.
 9. The annunciation system of claim 8, wherein the electronic controller comprises a microprocessor mounted on a printed circuit board.
 10. The annunciation system of claim 9, wherein the printed circuit board includes an output port connected to the LED's.
 11. The annunciation system of claim 10, including an electrical cable that electrically connects the output port to at least one of the LED's.
 12. An annunciation system for an HVAC fan coil unit, comprising: a housing comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front panel defining an opening sized to permit maintenance of one or more components inside the housing; at least one light source on a substrate, the substrate mounted to the front panel and adjacent to the opening; a cover mounted to and parallel to and offset from the front panel, the cover overlapping the opening and covering the at least one light source; and an electronic controller coupled to memory, the electronic controller configured to electrically and automatically energize a predetermined one of the at least one light source to emit light, wherein light emitted from the energized at least one light source is deflected by the cover onto exposed portions of the front panel to cast an indirectly visible glow indicative of a status, condition, or fault of the HVAC fan coil unit.
 13. The annunciation system of claim 12, wherein the electronic controller comprises a microprocessor mounted on a printed circuit board.
 14. The annunciation system of claim 13, wherein the printed circuit board includes an output port connected to the at least one light source.
 15. The annunciation system of claim 14, including an electrical cable that electrically connects the output port to the at least one light source, and the at least one light source comprises at least one LED.
 16. An annunciation system for an HVAC fan coil unit, comprising: a housing comprising a top panel, a bottom panel, opposed side panels, a rear panel, and a front panel, wherein the front panel is removable to permit maintenance of one or more components inside the housing, the front panel comprising a plurality of louvres to permit return air to be drawn into the HVAC fan coil unit; at least one LED on at least one substrate, the at least one substrate mounted to a frame member inside the housing; and an electronic controller coupled to memory, the electronic controller configured to electrically and automatically energize a predetermined one of the at least one LED on the at least one substrate to emit light, wherein light emitted from the energized at least one LED is allowed to pass through at least one of the louvres to convey a status, condition, or fault of the HVAC fan coil unit.
 17. The annunciation system of claim 16, wherein the at least one substrate comprises a pair substrates.
 18. The annunciation system of claim 17, wherein each of the substrates comprises a plurality of spaced apart LED's arranged in at least one row.
 19. The annunciation system of claim 16, wherein each of the substrates are mounted inside the housing in proximity to at least some of the plurality of louvres.
 20. The annunciation system of claim 16, wherein light emitted from the energized at least one LED comprises one of a plurality of colors, wherein each of the colors conveys a different status, condition, or fault of the HVAC fan coil unit. 